aboutsummaryrefslogtreecommitdiffstats
blob: b724ef7005de6745bdd8856a8ab50d68bbef06ed (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
/*
 * VMware VMCI Driver
 *
 * Copyright (C) 2012 VMware, Inc. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation version 2 and no later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

#ifndef _VMW_VMCI_DEF_H_
#define _VMW_VMCI_DEF_H_

#include <linux/atomic.h>

/* Register offsets. */
#define VMCI_STATUS_ADDR      0x00
#define VMCI_CONTROL_ADDR     0x04
#define VMCI_ICR_ADDR	      0x08
#define VMCI_IMR_ADDR         0x0c
#define VMCI_DATA_OUT_ADDR    0x10
#define VMCI_DATA_IN_ADDR     0x14
#define VMCI_CAPS_ADDR        0x18
#define VMCI_RESULT_LOW_ADDR  0x1c
#define VMCI_RESULT_HIGH_ADDR 0x20

/* Max number of devices. */
#define VMCI_MAX_DEVICES 1

/* Status register bits. */
#define VMCI_STATUS_INT_ON     0x1

/* Control register bits. */
#define VMCI_CONTROL_RESET        0x1
#define VMCI_CONTROL_INT_ENABLE   0x2
#define VMCI_CONTROL_INT_DISABLE  0x4

/* Capabilities register bits. */
#define VMCI_CAPS_HYPERCALL     0x1
#define VMCI_CAPS_GUESTCALL     0x2
#define VMCI_CAPS_DATAGRAM      0x4
#define VMCI_CAPS_NOTIFICATIONS 0x8

/* Interrupt Cause register bits. */
#define VMCI_ICR_DATAGRAM      0x1
#define VMCI_ICR_NOTIFICATION  0x2

/* Interrupt Mask register bits. */
#define VMCI_IMR_DATAGRAM      0x1
#define VMCI_IMR_NOTIFICATION  0x2

/* Maximum MSI/MSI-X interrupt vectors in the device. */
#define VMCI_MAX_INTRS 2

/*
 * Supported interrupt vectors.  There is one for each ICR value above,
 * but here they indicate the position in the vector array/message ID.
 */
enum {
	VMCI_INTR_DATAGRAM = 0,
	VMCI_INTR_NOTIFICATION = 1,
};

/*
 * A single VMCI device has an upper limit of 128MB on the amount of
 * memory that can be used for queue pairs.
 */
#define VMCI_MAX_GUEST_QP_MEMORY (128 * 1024 * 1024)

/*
 * Queues with pre-mapped data pages must be small, so that we don't pin
 * too much kernel memory (especially on vmkernel).  We limit a queuepair to
 * 32 KB, or 16 KB per queue for symmetrical pairs.
 */
#define VMCI_MAX_PINNED_QP_MEMORY (32 * 1024)

/*
 * We have a fixed set of resource IDs available in the VMX.
 * This allows us to have a very simple implementation since we statically
 * know how many will create datagram handles. If a new caller arrives and
 * we have run out of slots we can manually increment the maximum size of
 * available resource IDs.
 *
 * VMCI reserved hypervisor datagram resource IDs.
 */
enum {
	VMCI_RESOURCES_QUERY = 0,
	VMCI_GET_CONTEXT_ID = 1,
	VMCI_SET_NOTIFY_BITMAP = 2,
	VMCI_DOORBELL_LINK = 3,
	VMCI_DOORBELL_UNLINK = 4,
	VMCI_DOORBELL_NOTIFY = 5,
	/*
	 * VMCI_DATAGRAM_REQUEST_MAP and VMCI_DATAGRAM_REMOVE_MAP are
	 * obsoleted by the removal of VM to VM communication.
	 */
	VMCI_DATAGRAM_REQUEST_MAP = 6,
	VMCI_DATAGRAM_REMOVE_MAP = 7,
	VMCI_EVENT_SUBSCRIBE = 8,
	VMCI_EVENT_UNSUBSCRIBE = 9,
	VMCI_QUEUEPAIR_ALLOC = 10,
	VMCI_QUEUEPAIR_DETACH = 11,

	/*
	 * VMCI_VSOCK_VMX_LOOKUP was assigned to 12 for Fusion 3.0/3.1,
	 * WS 7.0/7.1 and ESX 4.1
	 */
	VMCI_HGFS_TRANSPORT = 13,
	VMCI_UNITY_PBRPC_REGISTER = 14,
	VMCI_RPC_PRIVILEGED = 15,
	VMCI_RPC_UNPRIVILEGED = 16,
	VMCI_RESOURCE_MAX = 17,
};

/*
 * struct vmci_handle - Ownership information structure
 * @context:    The VMX context ID.
 * @resource:   The resource ID (used for locating in resource hash).
 *
 * The vmci_handle structure is used to track resources used within
 * vmw_vmci.
 */
struct vmci_handle {
	u32 context;
	u32 resource;
};

#define vmci_make_handle(_cid, _rid) \
	(struct vmci_handle){ .context = _cid, .resource = _rid }

static inline bool vmci_handle_is_equal(struct vmci_handle h1,
					struct vmci_handle h2)
{
	return h1.context == h2.context && h1.resource == h2.resource;
}

#define VMCI_INVALID_ID ~0
static const struct vmci_handle VMCI_INVALID_HANDLE = {
	.context = VMCI_INVALID_ID,
	.resource = VMCI_INVALID_ID
};

static inline bool vmci_handle_is_invalid(struct vmci_handle h)
{
	return vmci_handle_is_equal(h, VMCI_INVALID_HANDLE);
}

/*
 * The below defines can be used to send anonymous requests.
 * This also indicates that no response is expected.
 */
#define VMCI_ANON_SRC_CONTEXT_ID   VMCI_INVALID_ID
#define VMCI_ANON_SRC_RESOURCE_ID  VMCI_INVALID_ID
static const struct vmci_handle VMCI_ANON_SRC_HANDLE = {
	.context = VMCI_ANON_SRC_CONTEXT_ID,
	.resource = VMCI_ANON_SRC_RESOURCE_ID
};

/* The lowest 16 context ids are reserved for internal use. */
#define VMCI_RESERVED_CID_LIMIT ((u32) 16)

/*
 * Hypervisor context id, used for calling into hypervisor
 * supplied services from the VM.
 */
#define VMCI_HYPERVISOR_CONTEXT_ID 0

/*
 * Well-known context id, a logical context that contains a set of
 * well-known services. This context ID is now obsolete.
 */
#define VMCI_WELL_KNOWN_CONTEXT_ID 1

/*
 * Context ID used by host endpoints.
 */
#define VMCI_HOST_CONTEXT_ID  2

#define VMCI_CONTEXT_IS_VM(_cid) (VMCI_INVALID_ID != (_cid) &&		\
				  (_cid) > VMCI_HOST_CONTEXT_ID)

/*
 * The VMCI_CONTEXT_RESOURCE_ID is used together with vmci_make_handle to make
 * handles that refer to a specific context.
 */
#define VMCI_CONTEXT_RESOURCE_ID 0

/*
 * VMCI error codes.
 */
enum {
	VMCI_SUCCESS_QUEUEPAIR_ATTACH	= 5,
	VMCI_SUCCESS_QUEUEPAIR_CREATE	= 4,
	VMCI_SUCCESS_LAST_DETACH	= 3,
	VMCI_SUCCESS_ACCESS_GRANTED	= 2,
	VMCI_SUCCESS_ENTRY_DEAD		= 1,
	VMCI_SUCCESS			 = 0,
	VMCI_ERROR_INVALID_RESOURCE	 = (-1),
	VMCI_ERROR_INVALID_ARGS		 = (-2),
	VMCI_ERROR_NO_MEM		 = (-3),
	VMCI_ERROR_DATAGRAM_FAILED	 = (-4),
	VMCI_ERROR_MORE_DATA		 = (-5),
	VMCI_ERROR_NO_MORE_DATAGRAMS	 = (-6),
	VMCI_ERROR_NO_ACCESS		 = (-7),
	VMCI_ERROR_NO_HANDLE		 = (-8),
	VMCI_ERROR_DUPLICATE_ENTRY	 = (-9),
	VMCI_ERROR_DST_UNREACHABLE	 = (-10),
	VMCI_ERROR_PAYLOAD_TOO_LARGE	 = (-11),
	VMCI_ERROR_INVALID_PRIV		 = (-12),
	VMCI_ERROR_GENERIC		 = (-13),
	VMCI_ERROR_PAGE_ALREADY_SHARED	 = (-14),
	VMCI_ERROR_CANNOT_SHARE_PAGE	 = (-15),
	VMCI_ERROR_CANNOT_UNSHARE_PAGE	 = (-16),
	VMCI_ERROR_NO_PROCESS		 = (-17),
	VMCI_ERROR_NO_DATAGRAM		 = (-18),
	VMCI_ERROR_NO_RESOURCES		 = (-19),
	VMCI_ERROR_UNAVAILABLE		 = (-20),
	VMCI_ERROR_NOT_FOUND		 = (-21),
	VMCI_ERROR_ALREADY_EXISTS	 = (-22),
	VMCI_ERROR_NOT_PAGE_ALIGNED	 = (-23),
	VMCI_ERROR_INVALID_SIZE		 = (-24),
	VMCI_ERROR_REGION_ALREADY_SHARED = (-25),
	VMCI_ERROR_TIMEOUT		 = (-26),
	VMCI_ERROR_DATAGRAM_INCOMPLETE	 = (-27),
	VMCI_ERROR_INCORRECT_IRQL	 = (-28),
	VMCI_ERROR_EVENT_UNKNOWN	 = (-29),
	VMCI_ERROR_OBSOLETE		 = (-30),
	VMCI_ERROR_QUEUEPAIR_MISMATCH	 = (-31),
	VMCI_ERROR_QUEUEPAIR_NOTSET	 = (-32),
	VMCI_ERROR_QUEUEPAIR_NOTOWNER	 = (-33),
	VMCI_ERROR_QUEUEPAIR_NOTATTACHED = (-34),
	VMCI_ERROR_QUEUEPAIR_NOSPACE	 = (-35),
	VMCI_ERROR_QUEUEPAIR_NODATA	 = (-36),
	VMCI_ERROR_BUSMEM_INVALIDATION	 = (-37),
	VMCI_ERROR_MODULE_NOT_LOADED	 = (-38),
	VMCI_ERROR_DEVICE_NOT_FOUND	 = (-39),
	VMCI_ERROR_QUEUEPAIR_NOT_READY	 = (-40),
	VMCI_ERROR_WOULD_BLOCK		 = (-41),

	/* VMCI clients should return error code within this range */
	VMCI_ERROR_CLIENT_MIN		 = (-500),
	VMCI_ERROR_CLIENT_MAX		 = (-550),

	/* Internal error codes. */
	VMCI_SHAREDMEM_ERROR_BAD_CONTEXT = (-1000),
};

/* VMCI reserved events. */
enum {
	/* Only applicable to guest endpoints */
	VMCI_EVENT_CTX_ID_UPDATE  = 0,

	/* Applicable to guest and host */
	VMCI_EVENT_CTX_REMOVED	  = 1,

	/* Only applicable to guest endpoints */
	VMCI_EVENT_QP_RESUMED	  = 2,

	/* Applicable to guest and host */
	VMCI_EVENT_QP_PEER_ATTACH = 3,

	/* Applicable to guest and host */
	VMCI_EVENT_QP_PEER_DETACH = 4,

	/*
	 * Applicable to VMX and vmk.  On vmk,
	 * this event has the Context payload type.
	 */
	VMCI_EVENT_MEM_ACCESS_ON  = 5,

	/*
	 * Applicable to VMX and vmk.  Same as
	 * above for the payload type.
	 */
	VMCI_EVENT_MEM_ACCESS_OFF = 6,
	VMCI_EVENT_MAX		  = 7,
};

/*
 * Of the above events, a few are reserved for use in the VMX, and
 * other endpoints (guest and host kernel) should not use them. For
 * the rest of the events, we allow both host and guest endpoints to
 * subscribe to them, to maintain the same API for host and guest
 * endpoints.
 */
#define VMCI_EVENT_VALID_VMX(_event) ((_event) == VMCI_EVENT_MEM_ACCESS_ON || \
				      (_event) == VMCI_EVENT_MEM_ACCESS_OFF)

#define VMCI_EVENT_VALID(_event) ((_event) < VMCI_EVENT_MAX &&		\
				  !VMCI_EVENT_VALID_VMX(_event))

/* Reserved guest datagram resource ids. */
#define VMCI_EVENT_HANDLER 0

/*
 * VMCI coarse-grained privileges (per context or host
 * process/endpoint. An entity with the restricted flag is only
 * allowed to interact with the hypervisor and trusted entities.
 */
enum {
	VMCI_NO_PRIVILEGE_FLAGS = 0,
	VMCI_PRIVILEGE_FLAG_RESTRICTED = 1,
	VMCI_PRIVILEGE_FLAG_TRUSTED = 2,
	VMCI_PRIVILEGE_ALL_FLAGS = (VMCI_PRIVILEGE_FLAG_RESTRICTED |
				    VMCI_PRIVILEGE_FLAG_TRUSTED),
	VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS = VMCI_NO_PRIVILEGE_FLAGS,
	VMCI_LEAST_PRIVILEGE_FLAGS = VMCI_PRIVILEGE_FLAG_RESTRICTED,
	VMCI_MAX_PRIVILEGE_FLAGS = VMCI_PRIVILEGE_FLAG_TRUSTED,
};

/* 0 through VMCI_RESERVED_RESOURCE_ID_MAX are reserved. */
#define VMCI_RESERVED_RESOURCE_ID_MAX 1023

/*
 * Driver version.
 *
 * Increment major version when you make an incompatible change.
 * Compatibility goes both ways (old driver with new executable
 * as well as new driver with old executable).
 */

/* Never change VMCI_VERSION_SHIFT_WIDTH */
#define VMCI_VERSION_SHIFT_WIDTH 16
#define VMCI_MAKE_VERSION(_major, _minor)			\
	((_major) << VMCI_VERSION_SHIFT_WIDTH | (u16) (_minor))

#define VMCI_VERSION_MAJOR(v)  ((u32) (v) >> VMCI_VERSION_SHIFT_WIDTH)
#define VMCI_VERSION_MINOR(v)  ((u16) (v))

/*
 * VMCI_VERSION is always the current version.  Subsequently listed
 * versions are ways of detecting previous versions of the connecting
 * application (i.e., VMX).
 *
 * VMCI_VERSION_NOVMVM: This version removed support for VM to VM
 * communication.
 *
 * VMCI_VERSION_NOTIFY: This version introduced doorbell notification
 * support.
 *
 * VMCI_VERSION_HOSTQP: This version introduced host end point support
 * for hosted products.
 *
 * VMCI_VERSION_PREHOSTQP: This is the version prior to the adoption of
 * support for host end-points.
 *
 * VMCI_VERSION_PREVERS2: This fictional version number is intended to
 * represent the version of a VMX which doesn't call into the driver
 * with ioctl VERSION2 and thus doesn't establish its version with the
 * driver.
 */

#define VMCI_VERSION                VMCI_VERSION_NOVMVM
#define VMCI_VERSION_NOVMVM         VMCI_MAKE_VERSION(11, 0)
#define VMCI_VERSION_NOTIFY         VMCI_MAKE_VERSION(10, 0)
#define VMCI_VERSION_HOSTQP         VMCI_MAKE_VERSION(9, 0)
#define VMCI_VERSION_PREHOSTQP      VMCI_MAKE_VERSION(8, 0)
#define VMCI_VERSION_PREVERS2       VMCI_MAKE_VERSION(1, 0)

#define VMCI_SOCKETS_MAKE_VERSION(_p)					\
	((((_p)[0] & 0xFF) << 24) | (((_p)[1] & 0xFF) << 16) | ((_p)[2]))

/*
 * The VMCI IOCTLs.  We use identity code 7, as noted in ioctl-number.h, and
 * we start at sequence 9f.  This gives us the same values that our shipping
 * products use, starting at 1951, provided we leave out the direction and
 * structure size.  Note that VMMon occupies the block following us, starting
 * at 2001.
 */
#define IOCTL_VMCI_VERSION			_IO(7, 0x9f)	/* 1951 */
#define IOCTL_VMCI_INIT_CONTEXT			_IO(7, 0xa0)
#define IOCTL_VMCI_QUEUEPAIR_SETVA		_IO(7, 0xa4)
#define IOCTL_VMCI_NOTIFY_RESOURCE		_IO(7, 0xa5)
#define IOCTL_VMCI_NOTIFICATIONS_RECEIVE	_IO(7, 0xa6)
#define IOCTL_VMCI_VERSION2			_IO(7, 0xa7)
#define IOCTL_VMCI_QUEUEPAIR_ALLOC		_IO(7, 0xa8)
#define IOCTL_VMCI_QUEUEPAIR_SETPAGEFILE	_IO(7, 0xa9)
#define IOCTL_VMCI_QUEUEPAIR_DETACH		_IO(7, 0xaa)
#define IOCTL_VMCI_DATAGRAM_SEND		_IO(7, 0xab)
#define IOCTL_VMCI_DATAGRAM_RECEIVE		_IO(7, 0xac)
#define IOCTL_VMCI_CTX_ADD_NOTIFICATION		_IO(7, 0xaf)
#define IOCTL_VMCI_CTX_REMOVE_NOTIFICATION	_IO(7, 0xb0)
#define IOCTL_VMCI_CTX_GET_CPT_STATE		_IO(7, 0xb1)
#define IOCTL_VMCI_CTX_SET_CPT_STATE		_IO(7, 0xb2)
#define IOCTL_VMCI_GET_CONTEXT_ID		_IO(7, 0xb3)
#define IOCTL_VMCI_SOCKETS_VERSION		_IO(7, 0xb4)
#define IOCTL_VMCI_SOCKETS_GET_AF_VALUE		_IO(7, 0xb8)
#define IOCTL_VMCI_SOCKETS_GET_LOCAL_CID	_IO(7, 0xb9)
#define IOCTL_VMCI_SET_NOTIFY			_IO(7, 0xcb)	/* 1995 */
/*IOCTL_VMMON_START				_IO(7, 0xd1)*/	/* 2001 */

/*
 * struct vmci_queue_header - VMCI Queue Header information.
 *
 * A Queue cannot stand by itself as designed.  Each Queue's header
 * contains a pointer into itself (the producer_tail) and into its peer
 * (consumer_head).  The reason for the separation is one of
 * accessibility: Each end-point can modify two things: where the next
 * location to enqueue is within its produce_q (producer_tail); and
 * where the next dequeue location is in its consume_q (consumer_head).
 *
 * An end-point cannot modify the pointers of its peer (guest to
 * guest; NOTE that in the host both queue headers are mapped r/w).
 * But, each end-point needs read access to both Queue header
 * structures in order to determine how much space is used (or left)
 * in the Queue.  This is because for an end-point to know how full
 * its produce_q is, it needs to use the consumer_head that points into
 * the produce_q but -that- consumer_head is in the Queue header for
 * that end-points consume_q.
 *
 * Thoroughly confused?  Sorry.
 *
 * producer_tail: the point to enqueue new entrants.  When you approach
 * a line in a store, for example, you walk up to the tail.
 *
 * consumer_head: the point in the queue from which the next element is
 * dequeued.  In other words, who is next in line is he who is at the
 * head of the line.
 *
 * Also, producer_tail points to an empty byte in the Queue, whereas
 * consumer_head points to a valid byte of data (unless producer_tail ==
 * consumer_head in which case consumer_head does not point to a valid
 * byte of data).
 *
 * For a queue of buffer 'size' bytes, the tail and head pointers will be in
 * the range [0, size-1].
 *
 * If produce_q_header->producer_tail == consume_q_header->consumer_head
 * then the produce_q is empty.
 */
struct vmci_queue_header {
	/* All fields are 64bit and aligned. */
	struct vmci_handle handle;	/* Identifier. */
	atomic64_t producer_tail;	/* Offset in this queue. */
	atomic64_t consumer_head;	/* Offset in peer queue. */
};

/*
 * struct vmci_datagram - Base struct for vmci datagrams.
 * @dst:        A vmci_handle that tracks the destination of the datagram.
 * @src:        A vmci_handle that tracks the source of the datagram.
 * @payload_size:       The size of the payload.
 *
 * vmci_datagram structs are used when sending vmci datagrams.  They include
 * the necessary source and destination information to properly route
 * the information along with the size of the package.
 */
struct vmci_datagram {
	struct vmci_handle dst;
	struct vmci_handle src;
	u64 payload_size;
};

/*
 * Second flag is for creating a well-known handle instead of a per context
 * handle.  Next flag is for deferring datagram delivery, so that the
 * datagram callback is invoked in a delayed context (not interrupt context).
 */
#define VMCI_FLAG_DG_NONE          0
#define VMCI_FLAG_WELLKNOWN_DG_HND 0x1
#define VMCI_FLAG_ANYCID_DG_HND    0x2
#define VMCI_FLAG_DG_DELAYED_CB    0x4

/*
 * Maximum supported size of a VMCI datagram for routable datagrams.
 * Datagrams going to the hypervisor are allowed to be larger.
 */
#define VMCI_MAX_DG_SIZE (17 * 4096)
#define VMCI_MAX_DG_PAYLOAD_SIZE (VMCI_MAX_DG_SIZE - \
				  sizeof(struct vmci_datagram))
#define VMCI_DG_PAYLOAD(_dg) (void *)((char *)(_dg) +			\
				      sizeof(struct vmci_datagram))
#define VMCI_DG_HEADERSIZE sizeof(struct vmci_datagram)
#define VMCI_DG_SIZE(_dg) (VMCI_DG_HEADERSIZE + (size_t)(_dg)->payload_size)
#define VMCI_DG_SIZE_ALIGNED(_dg) ((VMCI_DG_SIZE(_dg) + 7) & (~((size_t) 0x7)))
#define VMCI_MAX_DATAGRAM_QUEUE_SIZE (VMCI_MAX_DG_SIZE * 2)

struct vmci_event_payload_qp {
	struct vmci_handle handle;  /* queue_pair handle. */
	u32 peer_id;		    /* Context id of attaching/detaching VM. */
	u32 _pad;
};

/* Flags for VMCI queue_pair API. */
enum {
	/* Fail alloc if QP not created by peer. */
	VMCI_QPFLAG_ATTACH_ONLY = 1 << 0,

	/* Only allow attaches from local context. */
	VMCI_QPFLAG_LOCAL = 1 << 1,

	/* Host won't block when guest is quiesced. */
	VMCI_QPFLAG_NONBLOCK = 1 << 2,

	/* Pin data pages in ESX.  Used with NONBLOCK */
	VMCI_QPFLAG_PINNED = 1 << 3,

	/* Update the following flag when adding new flags. */
	VMCI_QP_ALL_FLAGS = (VMCI_QPFLAG_ATTACH_ONLY | VMCI_QPFLAG_LOCAL |
			     VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED),

	/* Convenience flags */
	VMCI_QP_ASYMM = (VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED),
	VMCI_QP_ASYMM_PEER = (VMCI_QPFLAG_ATTACH_ONLY | VMCI_QP_ASYMM),
};

/*
 * We allow at least 1024 more event datagrams from the hypervisor past the
 * normally allowed datagrams pending for a given context.  We define this
 * limit on event datagrams from the hypervisor to guard against DoS attack
 * from a malicious VM which could repeatedly attach to and detach from a queue
 * pair, causing events to be queued at the destination VM.  However, the rate
 * at which such events can be generated is small since it requires a VM exit
 * and handling of queue pair attach/detach call at the hypervisor.  Event
 * datagrams may be queued up at the destination VM if it has interrupts
 * disabled or if it is not draining events for some other reason.  1024
 * datagrams is a grossly conservative estimate of the time for which
 * interrupts may be disabled in the destination VM, but at the same time does
 * not exacerbate the memory pressure problem on the host by much (size of each
 * event datagram is small).
 */
#define VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE				\
	(VMCI_MAX_DATAGRAM_QUEUE_SIZE +					\
	 1024 * (sizeof(struct vmci_datagram) +				\
		 sizeof(struct vmci_event_data_max)))

/*
 * Struct used for querying, via VMCI_RESOURCES_QUERY, the availability of
 * hypervisor resources.  Struct size is 16 bytes. All fields in struct are
 * aligned to their natural alignment.
 */
struct vmci_resource_query_hdr {
	struct vmci_datagram hdr;
	u32 num_resources;
	u32 _padding;
};

/*
 * Convenience struct for negotiating vectors. Must match layout of
 * VMCIResourceQueryHdr minus the struct vmci_datagram header.
 */
struct vmci_resource_query_msg {
	u32 num_resources;
	u32 _padding;
	u32 resources[1];
};

/*
 * The maximum number of resources that can be queried using
 * VMCI_RESOURCE_QUERY is 31, as the result is encoded in the lower 31
 * bits of a positive return value. Negative values are reserved for
 * errors.
 */
#define VMCI_RESOURCE_QUERY_MAX_NUM 31

/* Maximum size for the VMCI_RESOURCE_QUERY request. */
#define VMCI_RESOURCE_QUERY_MAX_SIZE				\
	(sizeof(struct vmci_resource_query_hdr) +		\
	 sizeof(u32) * VMCI_RESOURCE_QUERY_MAX_NUM)

/*
 * Struct used for setting the notification bitmap.  All fields in
 * struct are aligned to their natural alignment.
 */
struct vmci_notify_bm_set_msg {
	struct vmci_datagram hdr;
	u32 bitmap_ppn;
	u32 _pad;
};

/*
 * Struct used for linking a doorbell handle with an index in the
 * notify bitmap. All fields in struct are aligned to their natural
 * alignment.
 */
struct vmci_doorbell_link_msg {
	struct vmci_datagram hdr;
	struct vmci_handle handle;
	u64 notify_idx;
};

/*
 * Struct used for unlinking a doorbell handle from an index in the
 * notify bitmap. All fields in struct are aligned to their natural
 * alignment.
 */
struct vmci_doorbell_unlink_msg {
	struct vmci_datagram hdr;
	struct vmci_handle handle;
};

/*
 * Struct used for generating a notification on a doorbell handle. All
 * fields in struct are aligned to their natural alignment.
 */
struct vmci_doorbell_notify_msg {
	struct vmci_datagram hdr;
	struct vmci_handle handle;
};

/*
 * This struct is used to contain data for events.  Size of this struct is a
 * multiple of 8 bytes, and all fields are aligned to their natural alignment.
 */
struct vmci_event_data {
	u32 event;		/* 4 bytes. */
	u32 _pad;
	/* Event payload is put here. */
};

/*
 * Define the different VMCI_EVENT payload data types here.  All structs must
 * be a multiple of 8 bytes, and fields must be aligned to their natural
 * alignment.
 */
struct vmci_event_payld_ctx {
	u32 context_id;	/* 4 bytes. */
	u32 _pad;
};

struct vmci_event_payld_qp {
	struct vmci_handle handle;  /* queue_pair handle. */
	u32 peer_id;	    /* Context id of attaching/detaching VM. */
	u32 _pad;
};

/*
 * We define the following struct to get the size of the maximum event
 * data the hypervisor may send to the guest.  If adding a new event
 * payload type above, add it to the following struct too (inside the
 * union).
 */
struct vmci_event_data_max {
	struct vmci_event_data event_data;
	union {
		struct vmci_event_payld_ctx context_payload;
		struct vmci_event_payld_qp qp_payload;
	} ev_data_payload;
};

/*
 * Struct used for VMCI_EVENT_SUBSCRIBE/UNSUBSCRIBE and
 * VMCI_EVENT_HANDLER messages.  Struct size is 32 bytes.  All fields
 * in struct are aligned to their natural alignment.
 */
struct vmci_event_msg {
	struct vmci_datagram hdr;

	/* Has event type and payload. */
	struct vmci_event_data event_data;

	/* Payload gets put here. */
};

/* Event with context payload. */
struct vmci_event_ctx {
	struct vmci_event_msg msg;
	struct vmci_event_payld_ctx payload;
};

/* Event with QP payload. */
struct vmci_event_qp {
	struct vmci_event_msg msg;
	struct vmci_event_payld_qp payload;
};

/*
 * Structs used for queue_pair alloc and detach messages.  We align fields of
 * these structs to 64bit boundaries.
 */
struct vmci_qp_alloc_msg {
	struct vmci_datagram hdr;
	struct vmci_handle handle;
	u32 peer;
	u32 flags;
	u64 produce_size;
	u64 consume_size;
	u64 num_ppns;

	/* List of PPNs placed here. */
};

struct vmci_qp_detach_msg {
	struct vmci_datagram hdr;
	struct vmci_handle handle;
};

/* VMCI Doorbell API. */
#define VMCI_FLAG_DELAYED_CB 0x01

typedef void (*vmci_callback) (void *client_data);

/*
 * struct vmci_qp - A vmw_vmci queue pair handle.
 *
 * This structure is used as a handle to a queue pair created by
 * VMCI.  It is intentionally left opaque to clients.
 */
struct vmci_qp;

/* Callback needed for correctly waiting on events. */
typedef int (*vmci_datagram_recv_cb) (void *client_data,
				      struct vmci_datagram *msg);

/* VMCI Event API. */
typedef void (*vmci_event_cb) (u32 sub_id, const struct vmci_event_data *ed,
			       void *client_data);

/*
 * We use the following inline function to access the payload data
 * associated with an event data.
 */
static inline const void *
vmci_event_data_const_payload(const struct vmci_event_data *ev_data)
{
	return (const char *)ev_data + sizeof(*ev_data);
}

static inline void *vmci_event_data_payload(struct vmci_event_data *ev_data)
{
	return (void *)vmci_event_data_const_payload(ev_data);
}

/*
 * Helper to read a value from a head or tail pointer. For X86_32, the
 * pointer is treated as a 32bit value, since the pointer value
 * never exceeds a 32bit value in this case. Also, doing an
 * atomic64_read on X86_32 uniprocessor systems may be implemented
 * as a non locked cmpxchg8b, that may end up overwriting updates done
 * by the VMCI device to the memory location. On 32bit SMP, the lock
 * prefix will be used, so correctness isn't an issue, but using a
 * 64bit operation still adds unnecessary overhead.
 */
static inline u64 vmci_q_read_pointer(atomic64_t *var)
{
#if defined(CONFIG_X86_32)
	return atomic_read((atomic_t *)var);
#else
	return atomic64_read(var);
#endif
}

/*
 * Helper to set the value of a head or tail pointer. For X86_32, the
 * pointer is treated as a 32bit value, since the pointer value
 * never exceeds a 32bit value in this case. On 32bit SMP, using a
 * locked cmpxchg8b adds unnecessary overhead.
 */
static inline void vmci_q_set_pointer(atomic64_t *var,
				      u64 new_val)
{
#if defined(CONFIG_X86_32)
	return atomic_set((atomic_t *)var, (u32)new_val);
#else
	return atomic64_set(var, new_val);
#endif
}

/*
 * Helper to add a given offset to a head or tail pointer. Wraps the
 * value of the pointer around the max size of the queue.
 */
static inline void vmci_qp_add_pointer(atomic64_t *var,
				       size_t add,
				       u64 size)
{
	u64 new_val = vmci_q_read_pointer(var);

	if (new_val >= size - add)
		new_val -= size;

	new_val += add;

	vmci_q_set_pointer(var, new_val);
}

/*
 * Helper routine to get the Producer Tail from the supplied queue.
 */
static inline u64
vmci_q_header_producer_tail(const struct vmci_queue_header *q_header)
{
	struct vmci_queue_header *qh = (struct vmci_queue_header *)q_header;
	return vmci_q_read_pointer(&qh->producer_tail);
}

/*
 * Helper routine to get the Consumer Head from the supplied queue.
 */
static inline u64
vmci_q_header_consumer_head(const struct vmci_queue_header *q_header)
{
	struct vmci_queue_header *qh = (struct vmci_queue_header *)q_header;
	return vmci_q_read_pointer(&qh->consumer_head);
}

/*
 * Helper routine to increment the Producer Tail.  Fundamentally,
 * vmci_qp_add_pointer() is used to manipulate the tail itself.
 */
static inline void
vmci_q_header_add_producer_tail(struct vmci_queue_header *q_header,
				size_t add,
				u64 queue_size)
{
	vmci_qp_add_pointer(&q_header->producer_tail, add, queue_size);
}

/*
 * Helper routine to increment the Consumer Head.  Fundamentally,
 * vmci_qp_add_pointer() is used to manipulate the head itself.
 */
static inline void
vmci_q_header_add_consumer_head(struct vmci_queue_header *q_header,
				size_t add,
				u64 queue_size)
{
	vmci_qp_add_pointer(&q_header->consumer_head, add, queue_size);
}

/*
 * Helper routine for getting the head and the tail pointer for a queue.
 * Both the VMCIQueues are needed to get both the pointers for one queue.
 */
static inline void
vmci_q_header_get_pointers(const struct vmci_queue_header *produce_q_header,
			   const struct vmci_queue_header *consume_q_header,
			   u64 *producer_tail,
			   u64 *consumer_head)
{
	if (producer_tail)
		*producer_tail = vmci_q_header_producer_tail(produce_q_header);

	if (consumer_head)
		*consumer_head = vmci_q_header_consumer_head(consume_q_header);
}

static inline void vmci_q_header_init(struct vmci_queue_header *q_header,
				      const struct vmci_handle handle)
{
	q_header->handle = handle;
	atomic64_set(&q_header->producer_tail, 0);
	atomic64_set(&q_header->consumer_head, 0);
}

/*
 * Finds available free space in a produce queue to enqueue more
 * data or reports an error if queue pair corruption is detected.
 */
static s64
vmci_q_header_free_space(const struct vmci_queue_header *produce_q_header,
			 const struct vmci_queue_header *consume_q_header,
			 const u64 produce_q_size)
{
	u64 tail;
	u64 head;
	u64 free_space;

	tail = vmci_q_header_producer_tail(produce_q_header);
	head = vmci_q_header_consumer_head(consume_q_header);

	if (tail >= produce_q_size || head >= produce_q_size)
		return VMCI_ERROR_INVALID_SIZE;

	/*
	 * Deduct 1 to avoid tail becoming equal to head which causes
	 * ambiguity. If head and tail are equal it means that the
	 * queue is empty.
	 */
	if (tail >= head)
		free_space = produce_q_size - (tail - head) - 1;
	else
		free_space = head - tail - 1;

	return free_space;
}

/*
 * vmci_q_header_free_space() does all the heavy lifting of
 * determing the number of free bytes in a Queue.  This routine,
 * then subtracts that size from the full size of the Queue so
 * the caller knows how many bytes are ready to be dequeued.
 * Results:
 * On success, available data size in bytes (up to MAX_INT64).
 * On failure, appropriate error code.
 */
static inline s64
vmci_q_header_buf_ready(const struct vmci_queue_header *consume_q_header,
			const struct vmci_queue_header *produce_q_header,
			const u64 consume_q_size)
{
	s64 free_space;

	free_space = vmci_q_header_free_space(consume_q_header,
					      produce_q_header, consume_q_size);
	if (free_space < VMCI_SUCCESS)
		return free_space;

	return consume_q_size - free_space - 1;
}


#endif /* _VMW_VMCI_DEF_H_ */